Although exploration for shale gas resources in China has only just begun, estimates are that its total resource base has already surpassed that of the United States. The chart shows proven reserves of gas (brown) – nearly all of them conventional – as opposed to shale gas reserves (tan) now deemed technically recoverable through the new technique of hydrological fracturing (fracking).

Russia leads all countries in conventional reserves followed by Iran, Qatar and Saudi Arabia. Most of these reserves are concentrated in Asia and the Middle East. Next comes the US, only slightly ahead of Algeria, with China having very little conventional gas.

When shale gas enters the picture, however, things change dramatically. China now leads the world in reserves followed by the US, Argentina, Mexico, Zambia, Australia, Canada, Libya, Brazil, Algeria, Poland and France. North America becomes an energy center with Africa and Europe making a contribution as well.

But this picture may not yet be complete. Notice that Russia, Iran and Qatar and Saudi Arabia are listed as not having any shale resources. This is because they already have so much conventional gas that they have not even bothered to look for shale deposits. When explorations eventually begin, these countries may prove to have enormous resources as well.

The total picture is that shale reserves are much more evenly distributed around the world than conventional gas resources. And they will eventually dwarf the gas that has been recovered through conventional techniques.